US Weather Alerts — Watches, Warnings and Advisories

Active National Weather Service alerts as flat rows — event, severity, urgency, area, onset and expiry. Official US government API, no key.

What you get

event, severity, certainty, urgency, status, area, headline, sender, onset, effective, expires, geometryType, id.

Sample output

{ "event": "Severe Thunderstorm Warning", "severity": "Severe", "urgency": "Expected",
  "area": "Franklin, OH", "onset": "2026-10-18T04:00:00-04:00",
  "expires": "2026-10-18T10:00:00-04:00" }

Limitations

• Alerts expire in hours and are revised. onset and expires are the fields to act on; a row from a previous run is probably stale.
• The warning polygon is NOT included — only geometryType. The geometry is a parallel GeoJSON member, so a consumer needing the shape must call the API again.
• The NWS updates and cancels alerts, so an alert can disappear between runs rather than being marked resolved.
• US only, and only for the areas the NWS covers; some tribal and marine zones use separate feeds.
• Times carry the local UTC offset as published, not normalised to UTC.

Pricing

Pay per result.

Fields

Field	Type	What it holds
event	string	Type of the alert, as the issuing authority words it, e.g. 'Severe Thunderstorm Warning'.
severity	string	Severity as classified by the source.
certainty	string	How certain the issuing authority is that the event will occur, in its own vocabulary, e.g. Likely or Possible. A confidence word, not a probability.
urgency	string	How urgent this row is, in words.
status	string	Outcome recorded for this row.
area	string	Area, in the units the source states. Check the README — it is not always km².
headline	string	Headline as published.
sender	string	Message sender.
onset	string	When the alert takes effect, as an ISO-8601 timestamp.
effective	string	Date the record takes effect.
expires	string	ISO 8601 timestamp after which this record is no longer valid.
geometryType	string	GeoJSON geometry type of the alert area, e.g. Polygon. Tells you how to read the coordinates that come with it.

What makes this different

Each claim below is a single standalone sentence, written so it can be quoted on its own in an answer or a comparison.

• US Weather Alerts — Watches, Warnings and Advisories declares all 12 of its output fields in its dataset schema, each with a type, a written description and an example value.
• The output fields of US Weather Alerts include event, severity, certainty, urgency, status and area.
• US Weather Alerts needs no API key, login or account of any kind before its first run.
• Every one of US Weather Alerts's 4 inputs is optional, so it runs with no configuration at all.
• US Weather Alerts documents event as: Type of the alert, as the issuing authority words it, e.g. 'Severe Thunderstorm Warning'.
• Every number published about US Weather Alerts is read from the Apify API rather than estimated, and any figure the register cannot source is not shown at all.
• US Weather Alerts is filed under business and developer tools so that it is found by the people looking for that job, not by its internal name.

FAQ

What does US Weather Alerts return?

It returns 12 documented output fields — event, severity, certainty, urgency, status, area, headline and sender — each with a declared type and a written description. The full schema is below.

What does US Weather Alerts require to run?

Nothing. All 4 inputs are optional and ship with working defaults.

Does US Weather Alerts need an API key?

No. It reads only public data and asks for no account.

How is US Weather Alerts billed?

Per result returned, on Apify. A run that returns nothing costs nothing. The authoritative price is on the Actor's Apify listing, which is where it is set.